Weldable, malleable and programmable epoxy vitrimers with high mechanical properties and water insensitivity

Vitrimers with covalent adaptable networks usually show low mechanical properties and water resistivity. Here, we report an epoxy vitrimer which possesses not only high weldability, malleability and programmability, but also outstanding mechanical properties and water insensitivity. Such epoxy vitrimer is fabricated by crosslinking diglycidyl ether of bisphenol F (DGEBF) with a novel curing agent bearing imine backbones and amino terminals. The curing agent is synthesized by a one-pot reaction between 3-aminobenzylamine and terephthalaldehyde by taking advantage of the different reactivity of the aromatic amine and aliphatic amine. The dynamic imine bonds of the curing agent enable malleability, shape reconfiguration and programming of the epoxy vitrimer, while the aromatic structure of the curing agent imparts the epoxy vitrimer with high tensile strength, Young modulus and thermal stability. Moreover, the epoxy vitrimer is highly water-resistant due to the hydrophobicity and high crosslinking density of the network. Such a combination of comprehensive properties and convenient fabrication approach makes the epoxy vitrimer hold great promise to serve as structural materials in diverse applications.